Insulated glass is heavily utilized in modern residential and commercial construction. In many areas of the country it is required by building code as an energy conservation measure. A single pane of glass alone has very little insulating value. Multi-pane insulated glass windows have much greater insulating value. Insulated glass units generally include at least two panes of glass having identical shapes. Sealants and adhesives are used to bond the glass panes to a perimeter spacer which separates the two panes of glass. The entire perimeter including the two panes of glass and the spacer are sealed to one another to eliminate movement of ambient air into the space between the two panes of glass.
The space is filled with dehydrated air or more commonly another gas such as argon, xenon or krypton. Sulfur hexafluoride is also used for gas filling. The filling of insulated glass units with argon or another gas that is not air has been found to increase the energy efficiency of the insulated glass units markedly. Some insulated glass units includes three panes of glass with two intervening spaces which are similarly filled with argon or another gas other than air and then edge sealed.
Fully robotic machinery exists to apply spacers to the edge of glass panes and to apply a secondary edge seal to partially complete insulated glass units. These machines generally include an application head that is made controllably movable by numerous servomotors and that moves in at least two and often three dimensions as well as rotating the application head as it is moved around the edges of the workpiece. These machines are effective but are complex and expensive.
The spacer in an insulated glass unit is inset from the peripheral edges of the glass panes leading to a trough shaped space bounded on two sides by the glass panes and on one side by the spacer. In the manufacturing of insulating glass units, this space is filled with an adhesive sealant which forms the, so called, secondary seal of the insulated glass unit. The secondary seal may be applied using a variety of different adhesive sealants. These include time setting sealants, such as silicones or butyl rubber sealants. Sometimes two part sealants utilizing a resin and a catalyst to polymerize the resin are utilized. More commonly in modern manufacturing, hot melt adhesive sealants are used. Hot melt adhesive sealants are general applied in a liquid state at a temperature of approximately 350° F. and harden upon cooling to ambient temperature.
In high volume manufacturing facilities, the secondary seal is commonly applied by fully automated equipment in which a computer controlled robotic sealant applying head is moved around the peripheral edges of the insulated glass unit under computer control and applies the sealant to the edge or edges of the insulated glass unit. Fully automated secondary edge sealing equipment of this sort can apply to the secondary seal to very large numbers of insulating glass units in a production run. Typically, the insulated glass units in these circumstances are produced in large runs of identical units.
Fully automated edge sealing equipment of this type requires highly precise computer numerically controlled programming in order to apply a consistent edge seal. Because of this and the requirement that the equipment be programmable to handle many different sizes and shapes of insulated glass units cause this sort of equipment to be quite expensive to purchase and maintain.
There also exist in the window and door manufacturing industry smaller manufacturing facilities at which short runs of custom made windows or doors are manufactured in small quantities or even in single unique units.
There is a need for simpler and less costly application devices in the window industry.